Interface properties of carbon fiber reinforced cyanate/epoxy resin composites at cryogenic temperature

2020 ◽  
Vol 40 (4) ◽  
pp. 291-299
Author(s):  
Meiling Yan ◽  
Chengwei Zhang ◽  
Weicheng Jiao ◽  
Jun Li ◽  
Yifan Huang ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Cryogenic Temperature ◽  
Shear Fracture ◽  
Fiber Reinforced ◽  
Interlaminar Fracture ◽  
Force Microscopy ◽  
Reinforced Plastics ◽  
Atomic Force ◽  
Microbond Test ◽  
Carbon Fiber Reinforced

AbstractThis study focuses on the influence of cryogenic temperature on the interface of carbon fiber reinforced plastics (CFRPs). Results of interfacial shear strength (IFSS) and mode II interlaminar fracture toughness (GIIC) at −196°C increased by 15.3% and 27.6% compared to the condition at room temperature (RT). By measuring the IFSS at −196°C, a new experimental method was designed based on microbond test. The layer shear fracture morphologies of CFRP were observed by atomic force microscopy and scanning electron microscopy, respectively. In order to study the interlaminar fracture mechanism, the interface and resin fracture hybrid model was built, and the shear-lag theory of interfacial toughness was adopted to analyze the energy release rate (Gdc) of microbond. The results showed that the Gdc value was increased by 11.5% from RT to −196°C temperature. A higher GIIC of CFRP was dominated by the higher IFSS and resin energy absorption at −196°C.

A micromechanical model of carbon fiber-reinforced plastic and steel hybrid laminate composites

2021 ◽  
pp. 002199832110075
Author(s):  
Minchang Sung ◽  
Hyunchul Ahn ◽  
Jinhyeok Jang ◽  
Dongil Kwon ◽  
Woong-Ryeol Yu
Keyword(s):  
Carbon Fiber ◽  
Compressive Stress ◽  
Fracture Strain ◽  
Matrix Material ◽  
Micromechanical Model ◽  
Fiber Reinforced ◽  
Laminate Composites ◽  
Reinforced Plastics ◽  
Carbon Fiber Reinforced ◽  
Hybrid Laminate

The fracture strain of carbon fiber-reinforced plastics (CFRPs) within CFRP/steel hybrid laminate composites is reportedly higher than that of CFRPs due to transverse compressive stress induced by the steel lamina. A micromechanical model was developed to explain this phenomenon and also to predict the mechanical behavior of CFRP/steel hybrid laminate composites. First, the shear lag theory was extended to calculate stress distributions on fibers and matrix material in a CFRP under multiaxial stress condition, considering three deformation states of matrix (elastic and plastic deformation and fracture) and the transverse compressive stress. Then, the deformation behavior of CFRP was predicted using average stress in the ineffective region and the Weibull distribution of carbon fibers. Finally, the mechanical properties of CFRP/steel hybrid laminate composites were predicted by considering the thermal residual stress generated during the manufacturing process. The micromechanical model revealed that increased transverse compressive stress decreases the ineffective lengths of partially broken fibers in the CFRP and results in increased fracture strain of the CFRP, demonstrating the validity of the current micromechanical model.

INCREASING SENSITIVITY OF EDDY CURRENT NON-DESTRUCTIVE TESTING OF DELAMINATION IN CARBON-FIBER REINFORCED PLASTICS

2021 ◽  
pp. 28-37
Author(s):  
P. N. Shkatov ◽  
G. A. Didin ◽  
A. A. Ermolaev
Keyword(s):  
Carbon Fiber ◽  
Eddy Current ◽  
Calculation Model ◽  
Fiber Reinforced ◽  
Destructive Testing ◽  
Carbon Fiber Reinforced Plastics ◽  
Reinforced Plastics ◽  
Fiber Reinforced Plastics ◽  
Carbon Fiber Reinforced ◽  
The Difference

The paper is concerned with increasing sensitivity of eddy current nondestructive testing of most dangerous delamination in carbon-fiber reinforced plastics (CFRP). Increased sensitivity is achieved by separate registration and comparison of eddy current signals obtained from a set of stratifications of carbon fibers with the same orientation. The separation of eddy current signals is possible due to pronounced anisotropy of the electrical conductivity of the layers dominant in the direction of the fibers of the corresponding layer. Eddy-current signals are registered by eddy current probes with maximum sensitivity in a given angular direction. Prior to the scan eddy current signals of the probe are leveled on a defect-free area. The influence of the working gap on the difference between the eddy current signals of the probe is suppressed by normalizing it according to one of the signals. The analysis of the registered signals from delamination has been performed using an approximate calculation model. The reliability of the obtained results has been confirmed by comparison with experimental results and calculations using the finite element method.

Rotary Ultrasonic Machining: Effects of Tool End Angle on Delamination of CFRP Drilling

2017 ◽  
Author(s):  
Palamandadige K. S. C. Fernando ◽  
Meng (Peter) Zhang ◽  
Zhijian Pei ◽  
Weilong Cong
Keyword(s):  
Carbon Fiber ◽  
Material Removal ◽  
Ultrasonic Machining ◽  
Fiber Reinforced ◽  
Rotary Ultrasonic Machining ◽  
Carbon Fiber Reinforced Plastics ◽  
Reinforced Plastics ◽  
Hole Making ◽  
Fiber Reinforced Plastics ◽  
Carbon Fiber Reinforced

Aerospace, automotive and sporting goods manufacturing industries have more interest on carbon fiber reinforced plastics due to its superior properties, such as lower density than aluminum; higher strength than high-strength metals; higher stiffness than titanium etc. Rotary ultrasonic machining is a hybrid machining process that combines the material removal mechanisms of diamond abrasive grinding and ultrasonic machining. Hole-making is the most common machining operation done on carbon fiber reinforced plastics, where delamination is a major issue. Delamination reduces structural integrity and increases assembly tolerance, which leads to rejection of a part or a component. Comparatively, rotary ultrasonic machining has been successfully applied to hole-making in carbon fiber reinforced plastics. As reported in the literature, rotary ultrasonic machining is superior to twist drilling of carbon fiber reinforced plastics in six aspects: cutting force, torque, surface roughness, delamination, tool life, and material removal rate. This paper investigates the effects of tool end angle on delamination in rotary ultrasonic machining of carbon fiber reinforced plastics. Several investigators have cited thrust force as a major cause for delamination. Eventhogh, it is found on this investigation, tool end angle has more significant influence on the delamination in rotary ultrasonic machining of carbon fiber reinforced plastics comparing to cutting force and torque.

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